In PQ News:

Call of the Month for February 2026

A PQ Knowledge funder contacted the PQ Hotline with questions about unusual waveform behavior observed during testing of a 125 VDC DC shunt motor used as a backup lube oil pump. The motor, supplied by a station battery and charger system, had experienced a field-loss event that produced alarming voltage and current signatures. The immediate concern was whether the electrical behavior made sense and what should be expected when a DC motor loses its shunt field. In particular, the PQ Knowledge funder wanted to understand the interaction between armature current, motor speed, and torque, and whether the measured values were reasonable for the motor involved.

Most Popular PQ Documents (Based on Clicks)

1. PQ Standards for System Compatibility
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EPRI Industrial PQ Training Videos

As a follow-up to our Industrial Power Quality training classes, we have posted these complementary training videos to help solidify the concepts for both utility members and their customers. The top three are listed here.

Visualizing PQ Drive Parameters for Improved Voltage Sag Ride-Through 
This video demonstrates the voltage sag susceptibility of AC drive systems and how to improve the drive’s robustness through parameter changes.

Understanding PLC Voltage Sag Ride-through: AC and DC Powered Systems 
This video demonstrates the differences in voltage sag ride-through between an AC powered PLC system and a DC Powered PLC system.

Power Conditioning to Enhance Control System Voltage Sag Ride-Through: The Constant-Voltage Transformer 
This video shows how a CVT can be utilized to harden the voltage sag response of an automated control system.

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